The invention discloses a drawing
optical fiber torsion control device, a control method and a multimode
optical fiber, which belong to the field of
optical fiber manufacturing. An optical
fiber torsion control device is added in the area below the optical
fiber sheath
coating curing device and above the traction wheel in the drawing channel, Furthermore, a periodic rotational force is applied to the optical
fiber in the direction perpendicular to the optical fiber through the optical fiber twist control device, so that the optical fiber is periodically twisted. In the present invention, by adding an optical fiber twisting control device, the optical fiber after the wire-drawing coated protective layer is cured is twisted and the twisting force is transmitted, so as to eliminate the disturbance of the irregular deformation of the cone shape in the melting cone area of the
graphite furnace when the optical fiber prefabricated part is drawn. The out-of-roundness of the optical fiber core is reduced, the
refractive index deviation of the optical fiber preform after drawing is improved, and the accuracy of the
refractive index distribution is improved. Due to the torsion and rotation of the optical fiber, the distribution of the unstable
residual stress in the optical fiber is optimized, which is beneficial to the correction of the deviation of the
refractive index distribution caused by the reduction of the
residual stress.